Create a deb package

[velovix]

This adds the necessary configuration and CI to build the CLI as a deb package. This is accomplished using dh-virtualenv, which allows us to package Python dependencies in a virtual environment. Using dh-virtualenv not only allows us to use our own versions of Python dependencies, it also isolates our dependencies from the rest of the system. This allows us to have our own isolated installation of Docker Compose as a dependency, whose version we can update at our own pace.

The deb also obsoletes the need to install curl and rsync for the user, since they can now be expressed as package dependencies. However, Docker is currently still being installed for the user. We could consider using Ubuntu's version of Docker if we're comfortable with supporting an older version.

This includes an overhaul of our configuration system, so that different distributions of the CLI can be distributed with different defaults. Defaults are now provided by a defaults.yaml file. The deb package is given its own custom defaults.yaml that is configured to use system package locations like /var/lib/brainframe instead of user-installed locations like /var/local/brainframe.

Unfortunately, dh-virtualenv requires that we have a setup.py because it runs python3 setup.py install to add the application code to the virtual environment. I've tried to keep the setup.py as minimal as possible, shelling out to Poetry when I can.

This change is, admittedly, not immediately useful on its own. We would need a PPA or our own repository to distribute this deb to users, and updated instructions to go along with it. We will probably want to provide a script similar to get-docker.sh that handles all the installation steps for the user so that we can preserve our single-line installation experience.

See #13, which this PR does not resolve on its own.

To-do before merge:

• Test on a clean Ubuntu 18.04 instance
• Test on a clean Ubuntu 20.04 instance
• Do extensive testing on the Pip version to ensure there aren't any regressions

[velovix]

If you want to try it out, the deb is available as a build artifact on CircleCI.

[BryceBeagle]

Do we need a matrix for each version of ubuntu?

[velovix]

I'm not sure. It doesn't seem like the resulting deb has any attachment to 18.04 specifically, and the deb installs fine on my local 20.04 installation. I imagine this will become more clear when we start trying to put this thing in a package repository.

[velovix]

Turns out you were right. I'm not sure how it worked before, but building the deb on one version and installing it on another breaks some stuff. I've made the build-deb step a matrix build for 18.04 and 20.04.

[velovix]

@BryceBeagle @apockill

Okay! I've added a new CI job to test the deb against an Ubuntu 20.04 instance. Unfortunately, CircleCI doesn't offer 18.04 machine instances, so we can't automatically test those. I've also done manual testing for the Pip version (admittedly through local a wheel, but the behavior should be the same from PyPI), Ubuntu 18.04 with its deb, and Ubuntu 20.04 with its deb. Everything appears to work just fine. PTAPTAL!

[apockill]

lgtm 📦

[BryceBeagle]

Wait, linting failed